Since the discovery of the retrovirus HTLV-III/LAV as the etiological agent of AIDS, research efforts directed toward the epidemiology, prevention, pathogenesis, and adequate treatment of both the underlying disease and its sequellae have been intensified. However, several aspects of the work have been hampered by the lack of relatively simple, rapid, and quantitative methods for detecting the virus or its constituent antigens in experimental systems or clinical materials. The successful development of improved methods would enhance research on all aspects of AIDS throughout the scientific community but would especially benefit work of the AIDSP toward the development of vaccines and therapeutic regimens. The lack of rapid, quantitative assays coupled with the present paucity of animal model systems for the infection makes the development of therapies and vaccines particularly difficult. The objective of this contract is to assure that simpler, faster, and quantitative methods for the detection of HTLV-III/LAV and related retroviruses will be developed in the most expeditious manner. The end product(s) of this research should permit the ready detection and measurement of HTLV-III/LAV and related retroviruses in clinical, animal and laboratory specimens.